title: Assessment of the suitability of mannitol salt agar for growing bovine-associated coagulase-negative staphylococci and its use under field conditions.
abstract: This study aimed at testing the applicability of mannitol salt agar (MSA), a medium generally used in human medicine for differentiating Staphylococcus aureus from coagulase-negative staphylococci (CNS), for culturing bovine-associated CNS species. All test isolates from a comprehensive collection of well-identified CNS species, including both reference strains and field isolates, were able to grow. Subsequently, bulk milk samples and teat apex swabs were used to examine the capability of MSA for yielding CNS under field conditions. Sixty-nine and 47 phenotypically different colonies were retrieved from bulk milk and teat apices, respectively. The majority of isolates from teat apices were staphylococci, whereas in bulk milk, staphylococci formed a minority. After 24h of growth, recovery of separate colonies of CNS was much more convenient on MSA compared to a non-selective blood agar. The results of this study indicate that MSA is a suitable medium for both growth and recovery of bovine-associated CNS.
authors.affiliation: M-team and Mastitis and Milk Quality Research Unit, Department of Reproduction, Obstetrics, and Herd Health, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. Anneleen.Devisscher@UGent.be
authors.forename: A
authors.initials: A
authors.lastname: De Visscher
authors.forename: F
authors.initials: F
authors.lastname: Haesebrouck
authors.forename: S
authors.initials: S
authors.lastname: Piepers
authors.forename: W
authors.initials: W
authors.lastname: Vanderhaeghen
authors.forename: K
authors.initials: K
authors.lastname: Supré
authors.forename: F
authors.initials: F
authors.lastname: Leroy
authors.forename: E
authors.initials: E
authors.lastname: Van Coillie
authors.forename: S
authors.initials: S
authors.lastname: De Vliegher
mesh_terms: D000362:Agar / Q000737:chemistry*; D000818:Animals; D001431:Bacteriological Techniques; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000382:microbiology; D003030:Coagulase / Q000378:metabolism*; D003612:Dairying; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D008353:Mannitol / Q000737:chemistry*; D008892:Milk / Q000382:microbiology; D013045:Species Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary; D013210:Staphylococcus / Q000201:enzymology* / Q000502:physiology*
chemical_list: D003030:Coagulase; D008353:Mannitol; D000362:Agar
keywords: Bulk milk; CNS; Coagulase-negative Staphylococcus species; Dairy cows; Mannitol salt agar